WO2011026797A1

WO2011026797A1 - Dye sensitised solar cell

Info

Publication number: WO2011026797A1
Application number: PCT/EP2010/062567
Authority: WO
Inventors: Junichi Tanabe; Hiroshi Yamamoto; Shinji Nakamichi; Ryuichi Takahashi
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2009-09-04
Filing date: 2010-08-27
Publication date: 2011-03-10
Anticipated expiration: 2012-03-04
Also published as: CN102598332A; US8709299B2; KR20120068017A; AU2010291376A1; US20120145238A1; TW201127813A; EP2474052A1; JP2013504151A; ZA201202364B

Abstract

The present invention pertains to an electrode layer comprising a porous film made of oxide semiconductor fine particles sensitized with certain methin dyes. Moreover the present invention pertains to a photoelectric conversion device comprising said electrode layer, a dye sensitized solar cell comprising said photoelectric conversion device and to novel methin dyes.

Description

Dye sensitised solar cell

Description

The present invention pertains to an electrode layer comprising a porous film made of oxide semiconductor fine particles sensitized with certain methin dyes. Moreover the present invention pertains to a photoelectric conversion device comprising said electrode layer, a dye sensitized solar cell comprising said photoelectric conversion device and to novel methin dyes. US2004/0187918, CN-C-1253436, JP-A-2005/082678 and JP-A-2007/149570 disclose photoelectric conversion devices comprising some methine dyes.

It is the finding of the present invention that photoelectric conversion devices sensitized with certain methin dyes have excellent overall properties, in particular that they have a particularly high photo-electric power conversion efficiency.

The present invention pertains to an electrode layer comprising a porous film made of oxide semiconductor fine particles sensitized with a dye of formula (I),

wherein

n is 1 -6, preferably 1 or 2, most preferably 1 ;

A is a group of formula (II) or (III), preferably a group of formula (II);

Y- is an inorganic or organic anion, preferably Ch, Br, h, SCN-, BF₄-, PF6^", CI0₄ ^", SbF6^", AsF6^", SO3^" or an organic anion selected from the group consisting of carboxylate, sul- phonate, sulphate, phosphate, phosphonate, more preferably Ch, Br or h, most preferably Br;

Ri and R2 are independently H, Ci-C2oalkyl whereby the alkyl is uninterrupted or interrupted by O, S, NRi₄ or combinations thereof, C6-C2oaryl, C₄-C2oheteroaryl, or C6- C2oaryl substituted by 1 -3 d-Csalkyl, preferably H;

or Ri can additionally be D; R29 is Ci-C2oalkyl which is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C2oaryl, C4-C2oheteroaryl, O^" (for instance, if R29 is O^", Y^" is not part of the compound of formula (I)), OR32, C7-C2oaralkyl, or C6-C2oaryl substituted by 1-3 Ci- Csalkyl, or C7-C2oaralkyl substituted at the aryl by 1-3 Ci-C₈alkyl, preferably R29 is Ci- C2oalkyl;

R30 is G, H, OR32, Ci-C2oalkyl whereby the alkyl is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C2oaryl, C4-C2oheteroaryl, or C6-C2oaryl substituted by 1-3 d-Csalkyl, preferably G or H, most preferably H;

R31 is H or preferably H;

R32 is Ci-C2oalkyl which is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C2oaryl, C4-C2oheteroaryl, or C6-C2oaryl substituted by 1-3 Ci-C₈alkyl;

G is -R28-COOH, -R₂₈-COO-Z⁺; -R₂₈-S0₃H, -R₂₈-S0₃-Z⁺; -R₂₈-OP(0)(0-Z⁺)₂, -R₂₈- OP(0)(OH)₂ or -R₂₈-OP(0)(OH)0-Z⁺, preferably -R₂₈-COOH or -R₂₈-COO Z⁺, most preferably -R₂₈-COOH;

R2₈ is a direct bond, Ci-C2oalkylene, C2-C4alkenylene or C6-Cioarylene, most preferably a direct bond;

Z⁺ is an organic or inorganic cation, preferably is N(Ri4)4⁺, Li⁺, Na⁺ or K⁺ or is an ammonium cation which is part of a compound of formula (I) as part of group A;

D V), preferably a group of formula

R

r substituted Ci-C2oalkyl, C2-C2oalkenyl, C2-C2oalkynyl, C6-C2oaryl, C4-C24heteroaryl, C7-C2oaralkyl, C₈-C2oaralkenyl, C₈- C2oaralkynyl, C4-C2ocycloalkyl, C5-C2ocycloalkenyl or C6-C2ocycloalkynyl, whereby the alkyl and cycloalkyl are uninterrupted or interrupted by O, S, NR14 or combinations thereof; or R17 and Ri₈, R17 and R22, R17 and R20 and/or Ri₈ and R19 form together an unsubstituted or substituted 5-, 6- or 7-membered ring; i5, i6, Ri9, R20, R21 , R22, R23 and R24 are independently H, N R25R26, OR25, SR25, NR25-NR26R27, NR25-OR26, O-CO-R25, O-CO-OR25, O-CO-NR25R26, NR25-CO-R26, NR25- CO-OR26, NR25-CO-NR26R27, CO-R25, CO-OR25, CO-NR25R26, S-CO-R25, CO-SR25, CO- NR25-NR26R27, CO-NR25-OR26, CO-O-CO-R25, CO-O-CO-OR25, CO-O-CO-NR25R26, CO-NR25-CO-R26, CO-NR25-CO-OR26, or unsubstituted or substituted Ci-C₂₀alkyl, C₆- C2oaryl, C2-C2oalkenyl, C2-C2oalkynyl, C6-C2oaryl, C4-C2oheteroaryl, C7-C2oaralkyl, Cs- C2oaralkenyl, C8-C2oaralkynyl, C4-C2ocycloalkyl, C5-C2ocycloalkenyl or C6- C2ocycloalkynyl, whereby the alkyl and cycloalkyi are uninterrupted or interrupted by O, S, NR14 or combinations thereof;

R25, R26 and R27 are independently H or unsubstituted or substituted Ci-C2oalkyl, C6- C2oaryl, C2-C2oalkenyl, C2-C2oalkynyl, C6-C2oaryl, C4-C2oheteroaryl, C7-C2oaralkyl, Cs- C2oaralkenyl, C8-C2oaralkynyl, C4-C2ocycloalkyl, C5-C2ocycloalkenyl or C6- C2ocycloalkynyl, whereby the alkyl and cycloalkyi are uninterrupted or interrupted by O, S, NR14 or combinations thereof;

Ri4 is H or Ci-C2oalkyl.

For instance, n is 1 or 2;

A is a group of formula (II) or (III),

Y^" is CI^", Br, I-, SCN-, BF4^", PF6^", CIO4^", SbF6^", AsF6^", SO3^" or an organic anion selected from the group consisting of Ci-C₂₀alkyl-COO-, C₆-C2oaryl-COO-, Ci-C₂oalkyl-S(=0)₂0-, C6-C2oaryl-S(=0)₂0-, Ci-C₂oalkyl-0-S(=0)₂0-, C6-C2oaryl-0-S(=0)₂0-, Ci-C₂₀alkyl- P(=0)₂0-, C6-C2oaryl-P(=0)₂0-, Ci-C₂oalkyl-0-P(=0)₂0- and C6-C2oaryl-0-P(=0)₂0-, whereby the aryl is unsubstituted or substituted by 1 to 4 Ci-C2oalkyl, or Y- is an anionic group which is part of a compound of formula (I) and is selected from the group con- sisting of COO^", SO3-, P(=0)(0-)(0^"Z⁺) or P(=0)(OH)(0^");

Ri and R2 are independently H, Ci-C2oalkyl whereby the alkyl is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C2oaryl, C4-C2oheteroaryl, or C6- C2oaryl substituted by 1-3 Ci-Csalkyl;

or Ri can additionally be D;

R29 is Ci-C2oalkyl which is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C2oaryl, C4-C2oheteroaryl, O^", OR32, C7-C2oaralkyl, or C6-C2oaryl substituted by 1-3 Ci-Csalkyl, or C₇-C2oaralkyl substituted at the aryl by 1-3 Ci-Csalkyl; R30 is G, H, OR32, Ci-C2oalkyl whereby the alkyl is uninterrupted or interrupted by O, S, N R14 or combinations thereof, C6-C2oaryl, C4-C2oheteroaryl, or C6-C2oaryl substituted by 1-3 d-Cealkyl;

R32 is Ci-C2oalkyl which is uninterrupted or interrupted by O, S, N R14 or combinations thereof, C6-C2oaryl, C4-C2oheteroaryl, or C6-C2oaryl substituted by 1-3 Ci-C₈alkyl; G is -R28-COOH, -R₂₈-COO-Z⁺; -R₂₈-S0₃H, -R₂₈-S0₃-Z⁺; -R₂₈-OP(0)(0-Z⁺)₂, -R₂₈- OP(0)(OH)₂ or -R₂₈-OP(0)(OH)0-Z⁺;

R2₈ is a direct bond, Ci-C2oalkylene, C2-C4alkenylene or C6-Cioarylene; Z⁺ is N(Ri4)4⁺, Li⁺, Na⁺ or K⁺ or is the cationic group which is part of a compound

//

of formula (I) as part of group A;

D is independently a group of formula (III) or (IV),

Ri7 and Ri₈ are independently fluorenyl, Ci-C2oalkyl, C2-C2oalkenyl, C2-C2oalkynyl, C6- C2oaryl, C4-C24heteroaryl, C7-C2oaralkyl, C₈-C2oaralkenyl, C₈-C2oaralkynyl, C4- C2ocycloalkyl, C5-C2ocycloalkenyl or C6-C2ocycloalkynyl, whereby the fluorenyl, alkyl and cycloalkyi are uninterrupted or interrupted by O, S, N R14 or combinations thereof, and whereby the alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, aralkenyl, aralkynyl, cycloalkyi, cycloalkenyl and cycloalkynyl are unsubstituted or substituted by tetrahydro- furanyl, halogen, S-R14, O-R14, CO-OR14, O-CO-R14, N R14R14', CON R14R14', N R14-CO- R14', S(=0)20Ri4, S(=0)20^"Z⁺ or combinations thereof, and the fluorenyl, aryl and heteroaryl can be further substituted by maleic anhydridyl, maleimidyl, indenyl, Ci-C2oalkyl, C2-C2oalkenyl, C2-C2oalkynyl, C7-C2oaralkyl, C₈-C2oaralkenyl, C₈-C2oaralkynyl, C4- C2ocycloalkyl, C5-C2ocycloalkenyl, C6-C2ocycloalkynyl or combinations thereof, whereby the maleic anhydridyl and maleimidyl are unsubstituted or substituted by Ci-C2oalkyl, C6-C2oaryl, phenyl-NR-uR or combinations thereof; or Ri7 and Ris form together with the N they are attached to piperidinyl, piperazinyl, morpholinyl, imidazolidinyl or pyrrollidinyl, each of which is unsubstituted or substituted by Ci-C2oalkyl, Ci-C2oalkylidene, benzo, trimethylene, tetramethylene or combinations thereof, which are unsubstituted or substituted by halogen, S-R-u, O-R-u, CO-OR-u, O- CO-R14, NR14R14', CONR14R14', NR14-CO-R14', S(=0)₂ORi4, S(=0)₂0-Z⁺ or combinations thereof;

or Ri7 and R22, R17 the N-atom R17 and

Ris

_M/

whereby in

each of said groups one or more H-atom can be replaced by Ci-C2oalkyl, Ci-

C2oalkylidene, phenyl or combinations thereof, in each of said groups two geminal H- atom can be replaced by Ci-C2oalkylidene, and/or in each of said groups two vicinal H- atoms can be replaced by benzo, trimethylene or tetramethylene, whereby the benzo is unsubstituted or substituted by methyl (fluoren-9-ylidene);

Ris, R16, Rig, R20, R21 , R22, R23 and R24 are independently H, NR25R26, OR25, SR25, NR25-NR26R27, NR25-OR26, O-CO-R25, O-CO-OR25, O-CO-NR25R26, NR25-CO-R26, NR25- CO-OR26, NR25-CO-NR26R27, CO-R25, CO-OR25, CO-NR25R26, CO-SR25, CO-NR25- NR26R27, CO-NR25-OR26, CO-O-CO-R25, CO-O-CO-OR25, CO-O-CO-NR25R26, CO- NR25-CO-R26, CO-NR25-CO-OR26, Ci-C₂₀alkyl, C₂-C₂oalkenyl, C₂-C₂oalkynyl, C₆-C2oaryl, C4-C2oheteroaryl, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C4-C2ocycloalkyl, C5- C2ocycloalkenyl or C6-C2ocycloalkynyl, whereby the alkyl and cycloalkyl are uninterrupted or interrupted by O, S, NR14 or combinations thereof, and whereby the alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkenyl and cycloalkynyl are unsubstituted or substituted by halogen, S-R14, O-R14, CO-OR14, O-CO-R14, NR14R14', CONR14R14', NR14-CO-R14', S(=0)₂ORi4, S(=0)₂0-Z⁺ or combinations thereof, and the aryl and heteroaryl can be further substituted by Ci-C2oalkyl, C2- C2oalkenyl, C2-C2oalkynyl, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C4- C2ocycloalkyl, C5-C2ocycloalkenyl, C6-C2ocycloalkynyl or combinations thereof;

R25, R26 and R27 are independently H, Ci-C2oalkyl, C6-C2oaryl, C2-C2oalkenyl, C2- C2oalkynyl, C6-C2oaryl, C4-C2oheteroaryl, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C4-C2ocycloalkyl, C5-C2ocycloalkenyl or C6-C2ocycloalkynyl, whereby the alkyl and cycloalkyl are uninterrupted or interrupted by O, S, NR14 or combinations thereof, and whereby the alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkenyl and cycloalkynyl are unsubstituted or substituted by pyridin- ium^*Y^", maleic anhydridyl, maleimidyl, halogen, S-R14, O-R14, CO-OR14, O-CO-R14, NR14R14', CONR14R14', NR14-CO-R14', S(=0)₂ORi4, S(=0)₂0-Z⁺ or combinations thereof, and the aryl and heteroaryl can be further substituted by Ci-C2oalkyl, C2-C2oalkenyl, C2- C2oalkynyl, C7-C2oaralkyl, C8-C2oaralkenyl, C8-C2oaralkynyl, C4-C2ocycloalkyl, C5- C2ocycloalkenyl, C6-C2ocycloalkynyl or combinations thereof, whereby the pyridinium, maleic anhydridyl, maleimidyl are unsusbstituted or substituted by Ci-C2oalkyl, C2- C2oalkenyl, C2-C2oalkynyl, C6-C2oaryl, C6-C2oaryl-0-Ri4, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C4-C2ocycloalkyl, C5-C2ocycloalkenyl, C6-C2ocycloalkynyl, S-R14, O-R14, CO-OR14, O-CO-R14, NR14R14', CONR14R14', NR14-CO-R14' or combinations thereof; Ri4 and R14' are independently H or Ci-C2oalkyl.

For instance, n is 1 or 2;

A is a group of formula (lla) or (l ib), preferably a group of formula (I la)

Y^" is CI^", Br, I-, SCN-, BF4^", PF6^", CIO4^", SbF6^", AsF6^", SO3^" or an organic anion selected from the group consisting of Ci-C₂₀alkyl-COO-, C₆-C2oaryl-COO-, Ci-C₂oalkyl-S(=0)₂0-, C6-C2oaryl-S(=0)₂0-, Ci-C₂oalkyl-0-S(=0)₂0-, C6-C2oaryl-0-S(=0)₂0-, Ci-C₂₀alkyl- P(=0)₂0-, C6-C2oaryl-P(=0)₂0-, Ci-C₂oalkyl-0-P(=0)₂0- and C6-C2oaryl-0-P(=0)₂0-, whereby the aryl is unsubstituted or substituted by 1 to 4 Ci-C2oalkyl, or Y- is an anionic group which is part of a compound of formula (I) and is selected from the group consisting of COO-; Ri and R2 are independently H, Ci-C2oalkyl or C6-C2oaryl;

or Ri can additionally be D;

R29 is Ci-C2oalkyl, O^", 0-Ci-C2oalkyl or C7-C2oaralkyl substituted at the aryl by 1 Ci Cealkyl;

G is -R28-COOH or -R₂₈-COO Z⁺;

R28 is a direct bond, C2-C4alkenylene or Cearylene; Z⁺ is N(Ri4)4⁺, Li⁺, Na⁺ or K⁺ or is the cationic group which is part of a compound

//

of formula (I) as part of group A;

D is a group of formula (I I I),

Ri7 and Ris are independently d-Csalkyl, C2-C8alkenyl, C6-C2oaryl, C4-C24heteroaryl, C7-C2oaralkyl, C8-C2oaralkenyl, Cs-Cioaralkynyl or C5-Ci2cycloalkyl, whereby the alkyl, alkenyl, aryl, heteroaryl, aralkyi, aralkenyl, aralkynyl and cycloalkyi, are unsubstituted or substituted by tetrahydrofuranyl, halogen, S-R-u, O-R-u, CO-OR-u, O-CO-R-u, NR14R14', CONR14R14', NR14-CO-R14' or combinations thereof, and the aryl and heteroaryl can be further substituted by d-Csalkyl, d-Csalkenyl or Cs-doaralkenyl;

H H

or Ri7 and R20 form together with the N-atom R17 and R18 are attached to ²_ ²

N

H₂ H₂ H₂ H₂ H₂ H₂ H H

2 ' '2

N^' ~ ^CH ₂ , N^' N^{'" "}S _OR ^"NH , whereby in each of said groups one or more H-atom can be replaced by Ci-C2oalkyl, C6-C2oaryl or combinations thereof, in each of said groups two geminal H-atom can be replaced by d- C2oalkylidene, and/or in each of said groups two vicinal H-atoms can be replaced by benzo, trimethylene or tetramethylene, whereby the benzo is unsubstituted or substituted by methyl (fluoren-9-ylidene);

Ris is H, NR25R26, OR₂₅, SR₂₅, O-CO-R25 or NR25-CO-R26;

R25 and R26 are independently H, Ci-C-ualkyl, G^aryl or C7-Cioaralkyl, whereby the alkyl, aryl and aralkyi are unsubstituted or substituted by pyridinium*Y-, halogen, S-R14, O-R14, CO-OR14, O-CO-R14, NR14R14', CONR14R14', NR14-CO-R14' or combinations thereof, and the pyridinium and aryl can be further substituted by d-Csalkyl; Ri4 and R14' are independently H or Ci-C2oalkyl.

For example, n is 1 ;

A is a group of formula (I la),

Y^" is CI^", Br or h, preferably h; Ri and R2 are H; R-29 is Ci-Csalkyl, preferably methyl;

R28 is a direct bond;

D is a group of formula (I I I),

Ri7 is Ci-Csalkyl, preferably methyl;

H H

or Ri7 and R20 form together with the N-atom R17 and R18 are attached to c-C^{2 or}

N" ^

H₂

H₂C ^CH2

N H R18 is Ci-Csalkyl (e.g. methyl), C6-C24heteroaryl or C6-C2oaryl, whereby the aryl is substituted by Cs-C2oaralkenyl;

Ri5, Rig, R20 and R21 are H. For instance, n is 1 or 2;

A is a group of formula (lla) or (lib), preferably a group of formula (l la), (^Nb)'

, CI^", Br, I-, SCN-, BF₄ ^", PF₆

CIO4^", SbF6^", AsF6^", SO3^" or an organic Inion selected from the group consisting of Ci- C₂₀alkyl-COO-, C₆-C2oaryl-COO-, Ci-C₂oalkyl-S(=0)₂0-, C6-C2oaryl-S(=0)₂0-, Ci- C₂oalkyl-0-S(=0)₂0-, C₆-C₂₀aryl-O-S(=O)₂O-, Ci-C₂₀alkyl-P(=O)₂O-, C₆-C₂₀aryl-P(=O)₂O- , Ci-C₂₀alkyl-O-P(=O)₂O- and C₆-C₂₀aryl-O-P(=O)₂O-, whereby the aryl is unsubstituted or substituted by 1 to 4 Ci-C₂oalkyl, or Y- is an anionic group which is part of a compound of formula (I) and is selected from the group consisting of COO-;

Ri and R₂ are independently H, Ci-C₂₀alkyl or C6-C₂oaryl;

or Ri can additionally be D;

R₂9 is Ci-C₂oalkyl, O^", 0-Ci-C₂oalkyl or C7-C₂₀aralkyl unsubstituted or substituted at the aryl by 1 Ci-CsalkyI; G is -R₂₈-COOH or -R₂₈-COO-Z⁺;

R₂8 is a direct bond, C₂-C₄alkenylene or Cearylene;

Z⁺ is N(Ri₄)₄ ⁺, Li⁺, Na⁺ or K⁺ or is the cationic group which is part of a compound

//

of formula (I) as part of group A;

D is a group of formula (III),

Ri7 and R18 are independently Ci-CsalkyI, C₂-Csalkenyl, C6-C₂oaryl, C₄-C₂₄heteroaryl, C7-C₂oaralkyl, Cs-C₂oaralkenyl, Cs-doaralkynyl or C5-Ci₂cycloalkyl, whereby the alkyl, alkenyl, aryl, heteroaryl, aralkyi, aralkenyl, aralkynyl and cycloalkyi, are unsubstituted or substituted by tetrahydrofuranyl, halogen, S-R14, O-R14, CO-OR14, O-CO-R14, N R14R14', CON R14R14', N R14-CO-R14' or combinations thereof, and the aryl and heteroaryl can be further substituted by Ci-CsalkyI, C₂-Csalkenyl or Cs-C₂oaralkenyl; or Ri7 and R20 and/or R18 and R19 form together with the N-atom R17 and R18 are at-

H₂ H₂ H₂ H₂ H₂ H₂ H₉ H₉

tached to _c ²__c ² , N CH₂ , N O S _or ^U~NH , whereby in each of said groups one or more H-atom can be replaced by Ci-C2oalkyl, C6-C2oaryl or combinations thereof, in each of said groups two geminal H-atom can be replaced by Ci-C2oalkylidene, and/or in each of said groups two vicinal H-atoms can be replaced by benzo, trimethylene or tetramethylene, whereby the benzo is unsubstituted or substituted by methyl (fluoren-9-ylidene);

Ri5 is H, N R25R26, OR₂₅, SR₂₅, O-CO-R25 or N R25-CO-R26;

R25 and R26 are independently H, Ci-C-ualkyl, Cearyl or Cz-Cioaralkyl, whereby the al- kyl, aryl and aralkyl are unsubstituted or substituted by pyridinium^*Y-, halogen, S-R14, O-R14, CO-OR14, O-CO-R14, N R14R14', CONR14R14', N R14-CO-R14' or combinations thereof, and the pyridinium and aryl can be further substituted by d-Csalkyl;

Ri4 and R14' are independently H or Ci-C2oalkyl. For example, n is 1 ;

A is a group of formula (I la),

R29 is Ci-C2oalkyl or C7-C2oaralkyl;

R28 is a direct bond; D is a group of formula (III),

i7 an 18 are n ependently d-Csalkyl, Cearyl substituted by Cs-C2oaralkenyl or are C4-C24heteroaryl;

or Ri7 and R20 and/or R18 and R19 form together with the N-atom R17 and R18 are at- tached to

R25 is Ci-CsalkyI or C7-Cioaralkyl.

In compounds of f (I), D is a donor moiety, A is an ac-

ceptor moiety and iety. So compounds of formula (I)

contain a donor, a spacer and an acceptor.

^* indicates a free valence. Some preferred donors D are:

In these spacers, the donor D is preferably attached to the left side of the spacers and the acceptor A is attached to the right side of the spacer.

Some preferred acceptors A are: 

0

f

Γ

0 .5

0

^•^.

_*

U ^s°^3"

e a ^•^. ^ΗΟ ζΪγ^ΟΗ

O 0

Br^"

I

D

0

The oxide semiconductor fine particles are, for instance, made of ΤΊΟ2, Sn02, WO3, ZnO, Nb₂0₅, Fe₂0₃, Zr0₂, MgO, W0₃, ZnO, CdS, ZnS, PbS, Bi₂S₃, CdSe, CdTe or combinations thereof, preferably made of Ti0₂.

For instance, the electrode layer comprises a dye of formula (I) or a mixture of dyes of formula (I) as the only dye(s).

Preferred is a porous film made of oxide semiconductor fine particles which is sensi- tized with a dye of formula (I) and one or more further dyes.

Examples of further dyes are metal complex dyes (preferably the metal is Ru, Pt, Ir, Rh, Re, Os, Fe, W, Cr, Mo, Ni, Co, Mn, Zn or Cu, more preferably Ru, Os or Fe, most preferably Ru) and/or organic dyes selected from the group consisting of indoline, courmarin, cyanine, merocyanine, hemicyanine, methin, azo, quinone, quinonimine, diketo-pyrrolo-pyrrole, quinacridone, squaraine, triphenylmethane, perylene, indigo, xanthene, eosin, rhodamine and combinations thereof. As further dyes organic dyes, in particular methin dyes are preferred. For instance, the further dye is different from dyes of formula (I). For instance, the molar ratio of a further dye to a dye of formula (I) is 1 :19 to 19:1 , preferably 1 :9 to 9:1 , more preferably 1 :5 to 5:1 , most preferably 1 :3 to 3:1.

For example, the dye is adsorbed together with an additive, preferably a co-adsorbent.

Examples of such additives are co-adsorbents selected from the group consisting of a steroid (preferably deoxycholic acid, dehydrodeoxcholic acid, chenodeoxycholic acid, cholic acid methyl ester, cholic acid sodium salt or combinations thereof), a crown ether, a cyclodextrine, a calixarene, a polyethyleneoxide and combinations thereof, especially a steroid such as chenodeoxycholic acid.

For example, the molar ratio of such an additive to a dye of formula (I) is 1000:1 to 1 :100, preferably 100:1 to 1 :10, most preferably 10:1 to 1 :2. For example, such an additive is not a dye.

The present invention also pertains to a photoelectric conversion device comprising an electrode layer as defined herein. Such photoelectric conversion devices usually comprise

(a) a transparent conductive electrode substrate layer,

(b) an electrode layer comprising a porous film made of oxide semiconductor fine particles sensitized with

(c) a dye of formula (I),

(d) a counter electrode layer, and

(e) an electrolyte layer (e.g. filled between the working electrode layer b and the counter electrode layer d).

The component (c) can also be a combination of a dye of formula (I) and one or more further dyes.

Preferably, the transparent conductive electrode substrate layer (a) contains (e.g. consists of)

(a-1 ) a transparent insulating layer and

(a-2) a transparent conductive layer.

The transparent conductive layer (a-2) is usually between the transparent insulating layer (a-1 ) and the electrode layer (b). Examples of the transparent insulating layer (a-1 ) include glass substrates of soda glass, fused quartz glass, crystalline quartz glass, synthetic quartz glass; heat resistant resin sheets such as a flexible film; metal sheets, transparent plastic sheets made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyether sulfone (PES); a polished plate of a ceramic, such as titanium oxide or alumina. Examples of transparent conductive layer (a-2) are conductive metal oxides such as ITO (indium-tin compounded oxide), IZO (indium-zinc compounded oxide), FTO (fluorine-doped tin oxide), zinc oxide doped with boron, gallium or aluminum, and niobium- doped titanium oxide. The thickness of the transparent conductive layer (a-2) is usually 0.1 to 5 μηη. The surface resistance is usually below 40 ohms/sq, preferably below 20 ohms/sq.

To improve the conductivity of the transparent conductive layer (a-2), it is possible to form a metal wiring layer on it, made of for instance silver, platinum, aluminum, nickel or titanium. The area ratio of the metal wiring layer is generally within the range that does not significantly reduce the light transmittance of the transparent conductive elec- trode substrate layer (a). When such a metal wiring layer is used, the metal wiring layer may be provided as a grid-like, stripe-like, or comb-like pattern.

The electrode layer (b) is usually between the transparent conductive electrode substrate layer (a) and the electrolyte layer (e).

The porous film of oxide semiconductor fine particles of the electrode layer (b) can be prepared by a hydrothermal process, a sol/gel process or high temperature hydrolysis in gas phase. The fine particles usually have an average particle diameter of from 1 nm to 1000 nm. Particles with different size can be blended and can be used as either sin- gle or multi-layered porous film. The porous film of the oxide semiconductor layer (b) has usually a thickness of from 0.5 to 50 μηη.

If desired, it is possible to form a blocking layer on the electrode layer (b) (usually between the surface of the electrode layer (b) and the dye (c)) and/or between the elec- trode layer (b) and the transparent conductive electrode substrate layer (a) to improve the performance of the electrode layer (b). An example of forming a blocking layer is immersing the electrode layer (b) into a solution of metal alkoxides such as titanium ethoxide, titanium isopropoxide and titanium butoxide, chlorides such as titanium chloride, tin chloride and zinc chloride, nitrides and sulfides and then drying or sintering the substrate. For instance, the blocking layer is made of a metal oxide (e.g. T1O2, S1O2, AI2O3, Zr02, MgO, Sn02, ZnO, EU2O3, and Nb20s or combinations threof) or a polymer (e.g. poly(phenylene oxide-co-2-allylphenylene oxide) or poly(methylsiloxane)). Details of the preparation of such layers are described in, for example, Electrochimica Acta, 1995, 40, 643; J. Phys. Chem. B, 2003, 107, 14394; J. Am. Chem. Soc, 2003, 125, 475; Chem. Lett, 2006, 35, 252; J. Phys. Chem. B, 2006, 1 10, 19191 ; J. Phys. Chem. B, 2001 , 105, 1422. The blocking layer may be applied to prevent undesired reaction. The blocking is usually dense and compact, and is usually thinner than the electrode layer (b).

Preferably, the counter electrode layer (d) contains (e.g. consists of)

(d-1 ) a conductive layer and

(d-2) an insulating layer.

The conductive layer (d-1 ) is usually between the insulating layer (d-2) and the electrolyte layer (e). For instance, the conductive layer (d-1 ) contains a conductive carbon (e.g. graphite, single walled carbon nanotubes, multiwalled carbon nanotubes, carbon nanofibers, carbon fibers, grapheme or carbon black), a conductive metal (e.g. gold or platinum), a metal oxide (e.g. ITO (indium-tin compounded oxide), IZO (indium-zinc compounded oxide), FTO (fluorine-doped tinoxide), zinc oxide doped with boron, gallium or alumi- num, and niobium-doped titanium oxide) or mixtures thereof.

Furthermore, the conductive layer (d-1 ) may be one obtained by forming a layer of platinum, carbon or the like (generally with a thickness of from 0.5 to 2,000nm), on a thin film of a conductive oxide semiconductor, such as ITO, FTO, or the like (generally with a thickness of from 0.1 to 5 μηη). The layer of platinum, carbon or the like is usually between the electrolyte layer (e) and the insulating layer (d-2).

Examples of the insulating layer (d-2) includes glass substrates of soda glass, fused quartz glass, crystalline quartz glass, synthetic quartz glass; heat resistant resin sheets such as a flexible film; metal sheets, transparent plastic sheets made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyether sulfone (PES); a polished plate of a ceramic, such as titanium oxide or alumina.

The dye (c) is usually disposed on the electrode layer (b) on that surface of the elec- trode layer (b) facing the electrolyte layer (e).

For adsorption of the dye (c) to the electrode layer (b), the electrode layer (b) may be immersed into a solution or a dispersion liquid of the dye. A concentration of the dye solution or dye dispersion liquid is not limited to, but preferably from 1 μΜ to 1 M, and is preferably 10μΜ to 0.1 M. The time period for the dye adsorption is preferably from 10 seconds to 1000 hours, more preferably from 1 minute to 200 hours, most preferably from 1 to 10 hours. The temperature for dye adsorption is preferably from room temperature to the boiling temperature of the solvent or the dispersion liquid. The adsorption may be carried out dipping, immersing or immersing with stirring. As the stirring method, a stirrer, supersonic dispersion, a ball mill, a paint conditioner, a sand mill or the like is employed, while the stirring method shall not be limited thereto. The solvent for dissolving or dispersing the dye (c) includes water, alcohol solvents such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, ethylene glycol and propylene glycol, ether solvents such as dioxane, diethyl ether, dimethoxyethane, tetrahy- drofuran, dioxolane, t-butyl methyl ether, ethylene glycol dialkyl ether, propylene glycol monomethyl ether acetate and propylene glycol methyl ether, ketone solvents such as acetone, amide solvents such as N,N-dimethylformamide, Ν,Ν-dimethylacetamide and N-methylpyrrolidone, nitrile solvents such as acetonitnle, methoxy acetonitrile, methoxy propionitrile, propionitrile and benzonitrile, carbonate solvents such as ethylene carbonate, propylene carbonate and diethyl carbonate,

heterocyclic compounds such as 3-methyl-2-oxazolidinone, dimethyl sulfoxide, sul- folane and γ-butyrolactone, halogenated hydrocarbon solvents such as dichloro- methane, chloroform, dichloroethane, trichloroethane, trichloroethylene, chloroben- zene, o-dichlorobenzene, 1 -chloronaphthalene, bromoform, bromobenzene, methyl iodide, iodobenzene and fluorobenzene and hydrocarbon solvents such as benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, cumene, n-pentane, n-hexane, n- octane, cyclohexane, methylcyclohexane, 1 ,5-hexadiene and cyclohexadiene. These may be used solely or in the form of a mixture containing two or more solvents. As a solvent, supercritical solvent such as supercritical carbon dioxide may be used. As dye (c) a dye of formula (I) may be adsorbed on the electrode layer (b) solely or in combination with one or more further dyes. The dyes adsorbed together are not limited to dyes of formula (I). Two or more dyes may be adsorbed on the electrode layer (b) one by one or all together by dissolving the dyes in a solvent. It is preferable to use the dyes with different absorption peaks in different wavelengths to absorb wide range of light wavelengths and generate higher current. The ratio of two or more dyes adsorbed on the electrode layer (b) is not limited but preferably each dye has molar ratio of more than 10 %.

For adsorption of the dye (c), an additive may be used in combination. The additive may be any one of an agent that has a function presumably for controlling dye adsorption. The additive includes a condensation agent such as thiol or a hydroxyl compound and a co-adsorbent. These may be used solely or a mixture of them. The molar ratio of the additive to the dye is preferably 0.01 to 1 ,000, more preferably 0.1 to 100. For instance, the dye-adsorbed electrode layer may be treated with amines such as 4- tert-butyl pyridine. As a treatment method, immersing the dye-sensitized electrode layer into amine solution which may be diluted with a solvent such as acetnitrile or ethanol can be employed.

In the above manner, the electrode layer of the present invention can be obtained. When the electrolyte layer (e) is in the form of solution or quasi-solid, the electrolyte layer (e) usually contains,

(e-1 ) electrolyte compound,

(e-2) solvent and/or ionic liquid, and

preferably (e-3) other additives.

Examples of the electrolyte compound (e-1 ) include a combination of a metal iodide such as lithium iodide, sodium iodide, potassium iodide, cesium iodide or calcium iodide with iodine, a combination of a quaternary ammonium iodide such as tetraal- kylammonium iodide, pyridium iodide or imidazolium iodide with iodine, a combination of a metal bromide such as lithium bromide, sodium bromide, potassium bromide, cesium bromide or calcium bromide with bromine, a combination of a quaternary ammonium bromide such as tetraalykylammonium bromide or pyridinium bromide with bromine, metal complexes such as ferrocyanic acid salt-ferricyanic acid salt or ferrocene- ferricynium ion, sulfur compounds such as sodium polysulfide and alkylthiolalkyldisul- fide, a viologen dye, hydroquinone-quinone, a combination of a nitroxide radical such as 2,2,6,6-tetramethyl-1 -piperidinyloxy (TEMPO) and oxoammonium salt and a combination of a verdazyl radical and a corresponding onium salt. The above electrolyte compounds (e-1 ) may be used solely or in the form of a mixture. As an electrolyte compound (e-1 ), there may be used a molten salt that is in a molten state at room temperature. When such a molten salt is used, particularly, it is not necessary to use a solvent.

The electrolyte compound (e-1 ) concentration in the electrolyte solution is preferably 0.05 to 20M, more preferably 0.1 to 15M.

For instance, the solvent (e-2) is nitrile solvents such as acetonitrile, methoxy acetoni- trile, methoxy propionitrile, propionitrile and benzonitrile, carbonate solvents such as ethylene carbonate, propylene carbonate and diethyl carbonate, alcohol solvents such as methanol, ethanol, isopropyl alcohol, t-butyl alcohol, ethylene glycol and propylene glycol, ether solvents such as dioxane, diethyl ether, dimethoxyethane, tetrahydrofuran, dioxolane, t-butyl methyl ether, ethylene glycol dialkyl ether, propylene glycol mono- methyl ether acetate and propylene glycol methyl ether, water, ketone solvents such as acetone, amide solvents such as N,N-dimethylformamide, Ν,Ν-dimethylacetamide and N-methylpyrrolidone, heterocyclic compounds such as 3-methyl-2-oxazolidinone, dimethyl sulfoxide, sulfolane and γ-butyrolactone, halogenated hydrocarbon solvents such as dichloromethane, chloroform, dichloroethane, trichloroethane, trichloroethyl- ene, chlorobenzene, o-dichlorobenzene, 1 -chloronaphthalene, bromoform, bromoben- zene, methyl iodide, iodobenzene and fluorobenzene and hydrocarbon solvents such as benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, cumene, n-pentane, n-hexane, n-octane, cyclohexane, methylcyclohexane, 1 ,5-hexadiene and cyclo- hexadiene or combinations of the above mentioned solvents and the ionic liquid is a quaternary imidazolium salt, a quaternary pyridinium salt, a quarternary ammonium salt or combinations thereof, preferably the anion of the salt is BF₄-, PF6^", F(HF)2^", F(HF)3^", bis(trifluoromethanesulfonyl)imide [(CF₃S0₂)₂N-], N(CN)₂-, C(CN)₃-, B(CN)₄-, SCN-, SeCN^", |-, IO3^" or combinations thereof.

For example, a photoelectric conversion device comprises a solvent (e.g. without an ionic liquid). For instance, a photoelectric conversion device comprises an ionic liquid (e.g. without a solvent). Examples of further additives (e-3) are lithium salts (especially 0.005 to 2.0M, preferably 0.1 to 0.7M) (e.g. LiCI0₄, LiS0₃CF₃ or Li(CF₃S0₂)N); guanidinium thiocyanate (especially 0.005 to 2.0M, preferably 0.01 to 1 .0M); pyridines (especially 0.005 to 2.0M, preferably 0.02 to 0.7M) (e.g. pyridine, tert-butylpyridine or polyvinylpyridine); imidazoles (especially 0.005 to 2.0M, preferably 0.01 to 1 .0M) (e.g. imidazole, methylimida- zole, ethylimidazole or propylimidazole); benzimidazoles (especially 0.005 to 2.0M, preferably 0.01 to 1 .0M) (e.g. benzimidazole, metylbenzimidazole, ethylbenzimidazole or propylbenzimidazole); quinolines (especially 0.005 to 2.0M, preferably 0.01 to 1 .0M), gelling agents (especially 0.1 to 50 wt.%, preferably 1.0 to 10wt.% based on the weight of the component e) (e.g. polyvinylidene fluoride, polyvinylidene fluoride - hexafluoro- propylene copolymer, polyethylene oxide derivatives, polyacrylonitrile derivatives or amino acid derivatives), nano particles (especially 0.1 to 50 wt.%, preferably 1 .0 to 10wt.% based on the weight of the component e) (e.g. conductive nano particles, in particular single-wall carbon nanotubes, multi-wall carboncarbon nanotubes or combinations thereof, carbon fibers, carbon black, polyaniline-carbon black composite, Ti0₂, Si0₂, Sn0₂ or clay mineral (e.g. kaolinite, smectite, talc, vermiculite, mica and swelling mica)); and combinations thereof.

In the present invention, an inorganic solid compound such as copper iodide, copper thiocyanide or the like, an organic hole-transporting material or an electron-transporting material can be used in place of the electrolyte layer (e).

The instant electrode layer, photoelectric conversion devices and DSC can be prepared as outlined in US4927721 , US5084365, US5350644 and US5525440 or in analogy thereto.

The present invention also pertains to a dye sensitized solar cell comprising a photoelectric conversion device as described herein.

The present invention also pertains to the use of a compound of formula (I) as defined herein as a dye in a dye sensitized solar cell.

The present invention further pertains to a compound of formula (I) as defined herein. The compounds of formula (I) can be prepared according to methods known in the

Compound of formula (I) can be prepared by condensation of the corresponding pyridinium salt and ketone as described below: in case of n=1 ;

In case of n at least 2;

For instance, the reaction conditions of the condensation of the quaternary salts with carbonyl compounds are reflux in ethanol in the presence of piperidine or pyrrolidine (see for instance, J. Chem. Soc. 1961 , 5074, Dyes & Pigments 2003, 58, 227), or heating in acetic anhydride (see for instance, Indian J. Chem. 1968, 6, 235.), or heating in acetic acid in a presence of ammonium acetate. Before condensation, the group G may be protected. Then after the condensation reaction, the protection group can be removed. A group G comprising COOH or COO^"Z⁺ can be protected by, for example, t-butyl group. Then after condensation reactions, the COO-t-butyl group can be converted into COOH or COO Z⁺. Or compounds of formula (I) can be prepared by condensation of the corresponding pyridine derivatives with carbonyl compounds, followed by quaternization to the corresponding pyridinium.

For instance, the starting material are partly items of commerce or can be obtained according to methods known in the art.

When a denotation (e.g. D, G, R1-R2, R14, R14', R25-R27) occurs more than once (e.g. twice) in a compound, this denotation may be different groups or the same group unless otherwise stated.

It is to be understood that alkyl interrupted by O, S, NR14 or combinations comprises at least 2 carbon atoms and in case of combinations comprises at least 3 carbon atoms. In the definitions the term alkyl comprises within the given limits of carbon atoms, for example methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl,

2-ethylbutyl, n-pentyl, isopentyl, 1 -methylpentyl, 1 ,3-dimethylbutyl, n-hexyl, 1 - methylhexyl, n-heptyl, 2-methylheptyl, 1 ,1 ,3,3-tetramethylbutyl, 1 -methylheptyl, 3- methylheptyl, n-octyl, 2-ethylhexyl, 1 ,1 ,3-trimethylhexyl, 1 ,1 ,3,3-tetramethylpentyl, nonyl, decyl, undecyl, 1 -methylundecyl or dodecyl.

Examples of alkenyl are within the given limits of carbon atoms vinyl, allyl, 1 - methylethenyl, and the branched and unbranched isomers of butenyl, pentenyl, hex- enyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl and dodecenyl. The term alkenyl also comprises residues with more than one double bond that may be conjugated or non-conjugated, for example may comprise one double bond. Examples of alkynyl are within the given limits of carbon atoms ethynyl, propargyl, 1 - methylethynyl, and the branched and unbranched isomers of butynyl, pentynyl, hexynyl, heptynyl, octynyl, nonynyl, decynyl, undecynyl and dodecynyl. The term alkynyl also comprises residues with more than one triple bond and residues with a triple bond and a double bond, all of which may be conjugated or non-conjugated. For in- stance, alkynyl comprises one triple bond.

Aryl is for example phenyl, biphenyl, naphthalinyl, anthracenyl, phenanthrenyl or pyrenyl, in particular phenyl or pyrenyl, especially phenyl. Aryl can be (further) substituted by .... is to be understood to include the aryl of aralkyl, aralkenyl and aralkynyl.

Heteroaryl may comprise one or more (e.g. 1 -4, in particular 1 -3, especially 1 -2, such as 1 heteroatom preferably selected from the group consisting of O, S and N, espe- cially S and N, in particular N). Examples of heteroaryl are thiophenyl, phenyl thiophenyl, diphenyl thiophenyl, triphenyl thiophenyl, bithiophenyl, terthiophenyl, tetrathio- phenyl, furanyl, bifuranyl, terfuranyl, pyrrolyl, carbazolyl, phenyl carbazolyl, diphenyl carbazolyl, triphenyl carbazolyl, tetraphenyl carbazolyl, indolyl, piperidinyl, 9H-purinyl,

pteridinyl, chinolinyl, isochinyl, acridinyl, phenazinyl,

, preferred examples are thiophenyl, phenyl thiophenyl, diphenyl thiophenyl, triphenyl thiophenyl, carbazolyl, phenyl carbazolyl, di- phenyl carbazolyl, triphenyl carbazolyl, tetraphenyl carbazolyl,

and iophenyl, triphenyl thiophenyl, carba-

zol

, phenyl carbazolyl, and , a particularly preferred example is phenyl carbazolyl. Heteroaryl as Ri₈ is for instance triphenyl thiophenyl, carbazolyl or phenyl carbazolyl, especially phenyl carbazolyl.

Methyl (fluoren-9-ylidene) is for instance

Aralkyl is for instance benzyl or α,α-dimethylbenzyl, especially benzyl.

An example of aralkynyl is 2-phenylethynyl.

Some examples of cycloalkyl are

, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, methylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl and dimethylcyclohexyl, for instance cyclohexyl. Some examples of cycloalkenyl are cyclopentenyl, cyclohexenyl, methylcyclopentenyl, dimethylcyclopentenyl and methylcyclohexenyl. Cycloalkenyl may comprise more than one double bond that may be conjugated or non-conjugated, for example may comprise one double bond.

Some examples of cycloalkynyl are cyclohexynyl and methylcyclohexenyl.

The term halogen may comprise fluorine, chlorine, bromine and iodine; for example halogen is fluorine.

In the definitions the term alkylene comprises within the given limits of carbon atoms, for example methylene, ethylene, propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, 2-ethylbutylene, n-pentylene, isopentylene, 1 - methylpentylene, 1 ,3-dimethylbutylene, n-hexylene, 1 -methylhexylene, n-heptylene, 2- methylheptylene, 1 ,1 ,3,3-tetramethylbutylene, 1 -methylheptylene, 3-methylheptylene, n-octylene, 2-ethylhexylene, 1 ,1 ,3-trimethylhexylene, 1 ,1 ,3,3-tetramethylpentylene, nonylene, decylene, undecylene, 1 -methylundecylene or dodecylene.

Examples of alkenylene are within the given limits of carbon atoms vinylene, allylene, 1 -methylethenylene, and the branched and unbranched isomers of butenylene. The term alkenylene also comprises residues with more than one double bond that may be conjugated or non-conjugated, for example may comprise one double bond.

Arylene is for example phenylene.

The preferences outlined herein apply to all aspects of the invention.

Ratio and % are weight ratio and weight-% unless otherwise stated. Abbreviations

DSC dye sensitized solar cell

Preparation Examples

Preparation of (A); 2.5 g (16.5 mmol) of methyl-6-methylnicotionate and 3.1 ml of methyliodide are dissolved in 15 ml of acetone and the solution is stirred reflux for 15 hours. After cooling down to the room temperature, the pale yellow precipitate is washed with acetone and dried under reduced pressure. 3.5 g of pale yellow solid (A) is obtained (yield 72 %).

Preparation of (B);

890 mg (0.30 mmol) of (A), 500 mg (0.34 mmol)of 4-dimethylaminobenzaldehyde, 26 mg (0.03 mmol) of piperidine and 18.2 mg (0.03 mmol) of acetic acid are dissolved in 10 ml of toluene and the solution is stirred at 1 10 °C for 15 hours. After cooling down to the room temperature, the reaction mixture is concentrated under reduced pressure. The crude product is purified by column chromatography and 1.1 g of (B) is obtained (85 %).

Preparation of C-1 ;

The mixture of 100 mg of pyridinium salt (B) and 3 ml of hydrobromic acid (48 % in

H2O) are stirred at 60 °C for 18 hours. After cooling down to the room temperature, the reaction mixture is concentrated under reduced pressure. The crude product is purified by column chromatography and 59 mg of C-1 is obtained (61 %).

Examples C-2 and C-3

Dyes C-2 and C-3 are prepared in analogy to the above-mentioned synthetic processes.

Examples C-4 and C-14

Dyes C-4 to C-14 are prepared in analogy to synthetic processes of C-1

No. Absorption

Chemical Structure

spectrum

Application of exam

Example A-1 (Preparation of DSC device)

Titanium oxide paste (PST-18NR, supplied by JGC Catalysts and Chemicals Ltd.) is applied onto an FTO (tin oxide doped with fluorine) glass substrate (< 12 ohms/sq, A1 1 U80, supplied by AGC Fabritech Co., Ltd.) by screen printing method to form a coating having an area size of 0.64 cm². After being dried for 5 minutes at 120°C, a working electrode layer having a thickness of 5 μηη is obtained by applying heat treatment in air at 450°C for 30 minutes and 500°C for 30 minutes.

0.02 g of a dye (C-1 ) is dissolved in 25 ml of a mixture solution of acetonitrile + t-butyl alcohol (1 :1 ). The above-prepared transparent working electrode is immersed in the solution at room temperature for 2 hours so as to adsorb the dye.

As a counter electrode, an ITO (indium-tin oxide) glass electrode substrate is prepared having a thickness of 8 nm electrode layer made of platinum formed thereon by sput- tering.

A solution of 0.05 M of iodine, 0.1 M of lithium iodide and 0.6 M of 1 -propyl-2,3- dimethylimidazolium iodide in methoxypropionitrile is used as an electrolytic solution. A photoelectric conversion device is fabricated by making the above working electrode and counter electrode opposed to each other and holding the above electrolyte solution between them with a spacer having 50μηη thickness.

The above photoelectric conversion device is evaluated under the illumination of an artificial sunlight (AM 1 .5, 100 mW/cm² intensity) generated by a solar simulator (Pec- cell Technologies, Inc) from the working electrode side. Examples A-2 to A-3

DSC device is prepared and evaluated in the same manner as described in the example A-1 except that the compound (C-1 ) is replaced with a compound (C-2) - (C-3).

Comparative example A-4 to A-5

DSC device is prepared and evaluated in the same manner as described in the example A-1 except that the compound (C-1 ) is replaced with a compound (R-1 ) - (R-2) shown below.

Table 1 shows the results.

Table 1 Example Compound Short-circuit Open-circuit Fill factor Photo-electric power current density voltage (V) (%) conversion efficiency (mA cm²) (%)

A-1 C-1 9.5 0.63 0.49 2.94

A-2 C-2 1 1.9 0.62 0.50 3.75

A-3 C-3 1 1.3 0.60 0.50 3.40

A-4^* R-1 9.8 0.50 0.52 2.54

A-5^* R-2 9.3 0.55 0.53 2.72

Comparison

As demonstrated in the examples, the dye of the present invention provide DSC device with excellent photovoltaic performance.

Example B-1 - B-4 (example of applying co-adsorbent)

DSC device is prepared and evaluated in the same manner as described in the example A-1 to A-4 except that additionally 8 mM of steroid compound (D-1 ) shown below is added to the dye solution.

(chenodeoxycholic acid)

Table 2 shows the results.

Table 2

Examples A-6 to A-16

DSC device is prepared and evaluated in the same manner as described in the example A-1 except that the compound (C-1 ) is replaced with a compound (C-4) - (C-14).

Table 4

Example Compound Short-circuit Open-circuit Fill factor Photo-electric power current density voltage (V) (%) conversion efficiency

(mA/cm²) (%) A-6 C-4 9.03 0.648 0.63 3.69

A-7 C-5 10.73 0.614 0.54 3.54

A-8 C-6 1 1.64 0.556 0.49 3.19

A-9 C-7 1 1.34 0.603 0.52 3.54

A-10 C-8 13.23 0.566 0.53 3.94

A-1 1 C-9 14.63 0.521 0.48 3.63

A-12 C-10 13.37 0.545 0.51 3.69

A-13 C-1 1 1 1.48 0.51 1 0.52 3.07

A-14 C-12 12.07 0.545 0.51 3.35

A-15 C-13 10.23 0.584 0.55 3.29

A-16 C-14 10.46 0.554 0.55 3.18

As demonstrated in the examples, combinations of the dye according to the present invention with the steroid compound provide DSC device with excellent photovoltaic performance.

Example B-5 (example of changing dye adsorption time)

DSC device is prepared and evaluated in the same manner as described in the example B-3 except that transparent working electrode is immersed in the dye solution at room temperature for 4 hours. Table 3 shows the results.

Table 3

Example Compound Short-circuit Open-circuit Fill factor Photo-electric power current density voltage (V) (%) conversion efficiency (mA/cm²) (%)

B-5 C-3 14.1 0.62 0.49 4.29

Claims

Dye sensitised solar cell WHAT IS CLAIMED:

1. An electrode layer comprising a porous film made of oxide semiconductor fine parti- cles sensitized with a dye of formula (I),

wherein

n is 1-6;

A is a group of formula (II) or (III)

Y- is an inorganic or organic anion;

Ri and R2 are independently H, Ci-C2oalkyl whereby the alkyl is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C2oaryl, C4-C2oheteroaryl, or d- C2oaryl substituted by 1-3 d-dalkyl;

or Ri can additionally be D;

R29 is Ci-C2oalkyl which is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C2oaryl, C4-C2oheteroaryl, O^", OR32, C7-C2oaralkyl, or C6-C2oaryl substituted by 1-3 d-dalkyl, or C₇-C2oaralkyl substituted at the aryl by 1-3 d-dalkyl;

R30 is G, H, OR32, Ci-C2oalkyl whereby the alkyl is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C2oaryl, C4-C2oheteroaryl, or C6-C2oaryl substituted by 1-3 d-Cealkyl;

R32 is d-doalkyl which is uninterrupted or interrupted by O, S, NR14 or combinations thereof, d-doaryl, d-doheteroaryl, or d-doaryl substituted by 1-3 d-dalkyl; G is -R28-COOH, -R₂₈-COO-Z⁺; -R₂₈-S0₃H, -R₂₈-S0₃-Z⁺; -R₂₈-OP(0)(0-Z⁺)₂, OP(0)(OH)₂ or -R₂₈-OP(0)(OH)0-Z⁺;

R₂₈ is a direct bond, Ci-C₂oalkylene, C₂-C₄alkenylene or C6-Cioarylene;

Z⁺ is an organic or inorganic cation;

D is independently a group of formula (III) or (IV),

Ri7 and Ri₈ are independently unsubstituted or substituted Ci-C₂oalkyl, C₂-C₂₀alkenyl, C₂-C₂₀alkynyl, C6-C₂oaryl, C₄-C₂₄heteroaryl, C7-C₂oaralkyl, C₈-C₂oaralkenyl, C₈- C₂₀aralkynyl, C₄-C₂ocycloalkyl, C5-C₂ocycloalkenyl or C6-C₂ocycloalkynyl, whereby the alkyl and cycloalkyi are uninterrupted or interrupted by O, S, NR14 or combinations thereof; or R17 and Ri₈, R17 and R₂₂, R17 and R₂o and/or Ri₈ and R19 form together an unsubstituted or substituted 5-, 6- or 7-membered ring;

Ri5, R16, Rig, R₂o, R₂i, R₂₂, R₂3 and R₂₄ are independently H, NR₂₅R₂e, OR₂₅, SR₂₅, NR₂₅-NR₂₆R₂₇, NR₂₅-OR₂₆, 0-CO-R₂₅, 0-CO-OR₂₅, 0-CO-NR₂₅R₂₆, NR₂₅-CO-R₂₆, NR₂₅- CO-OR₂₆, NR₂₅-CO-NR₂₆R₂₇, CO-R₂₅, CO-OR₂₅, CO-NR₂₅R₂₆, S-CO-R₂₅, CO-SR₂₅, CO- NR₂₅-NR₂₆R₂₇, CO-NR₂₅-OR₂₆, CO-0-CO-R₂₅, CO-0-CO-OR₂₅, CO-0-CO-NR₂₅R₂₆, CO-NR₂₅-CO-R₂₆, CO-NR₂₅-CO-OR₂₆, or unsubstituted or substituted Ci-C₂₀alkyl, C₆- C₂oaryl, C₂-C₂₀alkenyl, C₂-C₂₀alkynyl, C6-C₂oaryl, C₄-C₂oheteroaryl, C7-C₂oaralkyl, C₈- C₂₀aralkenyl, C₈-C₂oaralkynyl, C₄-C₂ocycloalkyl, C5-C₂ocycloalkenyl or C6- C₂ocycloalkynyl, whereby the alkyl and cycloalkyi are uninterrupted or interrupted by O, S, NR14 or combinations thereof;

R₂5, R₂6 and R₂7 are independently H or unsubstituted or substituted Ci-C₂oalkyl, C6- C₂oaryl, C₂-C₂₀alkenyl, C₂-C₂₀alkynyl, C6-C₂oaryl, C₄-C₂oheteroaryl, C7-C₂oaralkyl, C₈- C₂₀aralkenyl, C₈-C₂oaralkynyl, C₄-C₂ocycloalkyl, C5-C₂ocycloalkenyl or C6-

C₂ocycloalkynyl, whereby the alkyl and cycloalkyi are uninterrupted or interrupted by O, S, NR14 or combinations thereof;

Ri4 is H or Ci-C₂oalkyl.

2. An electrode layer according to claim 1 , wherein n is 1 or 2; is a group of formula (II) or

Y^" is CI^", Br, h, SCN-, BF4^", PF6^", CIO4^", SbF6^", AsF6^", SO3^" or an organic anion selected from the group consisting of Ci-C₂₀alkyl-COO-, C₆-C2oaryl-COO-, Ci-C₂oalkyl-S(=0)₂0-, C6-C2oaryl-S(=0)₂0-, Ci-C₂oalkyl-0-S(=0)₂0-, C₆-C₂₀aryl-O-S(=O)₂O-, Ci-C₂₀alkyl- P(=0)₂0^", C₆-C₂₀aryl-P(=O)₂O-, Ci-C₂₀alkyl-O-P(=O)₂O- and C₆-C₂₀aryl-O-P(=O)₂O-, whereby the aryl is unsubstituted or substituted by 1 to 4 Ci-C₂oalkyl, or Y- is an anionic group which is part of a compound of formula (I) and is selected from the group consisting of COO-, SO3-, P(=0)(0-)(0-Z⁺) or P(=0)(OH)(0^");

Ri and R₂ are independently H, Ci-C₂₀alkyl whereby the alkyl is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C₂oaryl, C4-C₂oheteroaryl, or C6- C₂₀aryl substituted by 1 -3 Ci-C₈alkyl;

or Ri can additionally be D;

R₂9 is Ci-C₂₀alkyl which is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C₂oaryl, C4-C₂oheteroaryl, O^", OR3₂, C7-C₂oaralkyl, or C6-C₂oaryl substituted by 1 -3 d-Cealkyl, or C₇-C₂₀aralkyl substituted at the aryl by 1 -3 d-Cealkyl;

R30 is G, H, OR3₂, Ci-C₂₀alkyl whereby the alkyl is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C₂oaryl, C4-C₂oheteroaryl, or C6-C₂oaryl substituted by 1 -3 d-Cealkyl;

R3₂ is Ci-C₂oalkyl which is uninterrupted or interrupted by O, S, NR14 or combinations thereof, C6-C₂oaryl, C4-C₂oheteroaryl, or C6-C₂oaryl substituted by 1 -3 Ci-C₈alkyl;

G is -R₂₈-COOH, -R₂₈-COO-Z⁺; -R₂₈-S0₃H, -R₂₈-S0₃-Z⁺; -R₂₈-OP(0)(C-Z⁺)₂, -R₂₈- OP(0)(OH)₂ or -R₂₈-OP(0)(OH)0-Z⁺;

R₂₈ is a direct bond, Ci-C₂oalkylene, C₂-C4alkenylene or C6-Cioarylene; Z⁺ is N(Ri₄)₄ ⁺, Li⁺, Na⁺ or K⁺ or is the cationic group which is part of a compound

//

of formula (I) as part of group A;

D is independently a group of formula (I I I) or (IV),

Ri7 and Ris are independently fluorenyl, Ci-C2oalkyl, C2-C2oalkenyl, C2-C2oalkynyl, C6- C2oaryl, C₄-C2₄heteroaryl, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C₄- C2ocycloalkyl, C5-C2ocycloalkenyl or C6-C2ocycloalkynyl, whereby the fluorenyl, alkyl and cycloalkyl are uninterrupted or interrupted by O, S, NRi₄ or combinations thereof, and whereby the alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkenyl and cycloalkynyl are unsubstituted or substituted by tetrahydro- furanyl, halogen, S-R14, O-R14, CO-OR-u, O-CO-R14, NRi₄Ri₄', CONRi₄Ri₄', NR-u-CO- R14', S(=0)20Ri4, S(=0)20^"Z⁺ or combinations thereof, and the fluorenyl, aryl and heteroaryl can be further substituted by maleic anhydridyl, maleimidyl, indenyl, Ci-C2oalkyl, C2-C2oalkenyl, C2-C2oalkynyl, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C₄-

C2ocycloalkyl, C5-C2ocycloalkenyl, C6-C2ocycloalkynyl or combinations thereof, whereby the maleic anhydridyl and maleimidyl are unsubstituted or substituted by Ci-C2oalkyl, C6-C2oaryl, phenyl-NRi₄Ri₄' or combinations thereof;

or Ri7 and R18 form together with the N they are attached to piperidinyl, piperazinyl, morpholinyl, imidazolidinyl or pyrrollidinyl, each of which is unsubstituted or substituted by Ci-C2oalkyl, Ci-C2oalkylidene, benzo, trimethylene, tetramethylene or combinations thereof, which are unsubstituted or substituted by halogen, S-R14, O-R14, CO-OR14, O- CO-R14, N R14R14', CONR14R14', NR14-CO-R14', S(=0)₂ORi4, S(=0)₂0-Z⁺ or combinations thereof;

or Ri7 and R22, R17 and R20 and/or R18 and R19 form together with the N-atom R17 and

H₂ H₂

^H2 ^H2 M"^{C_ C}TH ^H2 ^H2

Η, Η, _/C-C._ . ^N i ^M2 ^C-C.

Ris are attached to _r ²__r ² , N CH₂ , ^CH₂ , N O

N^' ^ ¹

_M/

whereby in

each of said groups one or more H-atom can be replaced by Ci-C2oalkyl, Ci- C2oalkylidene, phenyl or combinations thereof, in each of said groups two geminal H- atom can be replaced by Ci-C2oalkylidene, and/or in each of said groups two vicinal H- atoms can be replaced by benzo, trimethylene or tetramethylene, whereby the benzo is unsubstituted or substituted by methyl (fluoren-9-ylidene); i5, i6, ig, R20, R21 , R22, R23 and R24 are independently H, N R25R26, OR25, SR25, NR25-NR26R27, NR25-OR26, O-CO-R25, O-CO-OR25, O-CO-NR25R26, NR25-CO-R26, NR25- CO-OR26, NR25-CO-NR26R27, CO-R25, CO-OR25, CO-NR25R26, CO-SR25, CO-NR25- NR26R27, CO-NR25-OR26, CO-O-CO-R25, CO-O-CO-OR25, CO-O-CO-NR25R26, CO- NR25-CO-R26, CO-NR25-CO-OR26, Ci-C₂₀alkyl, C₂-C₂oalkenyl, C₂-C₂oalkynyl, C₆-C2oaryl, C4-C2oheteroaryl, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C4-C2ocycloalkyl, C5- C2ocycloalkenyl or C6-C2ocycloalkynyl, whereby the alkyl and cycloalkyl are uninterrupted or interrupted by O, S, NR14 or combinations thereof, and whereby the alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkenyl and cycloalkynyl are unsubstituted or substituted by halogen, S-R14, O-R14, CO-OR14, O-CO-R14, N R14R14', CONR14R14', NR14-CO-R14', S(=0)₂ORi4, S(=0)₂0-Z⁺ or combina- tions thereof, and the aryl and heteroaryl can be further substituted by Ci-C2oalkyl, C2- C2oalkenyl, C2-C2oalkynyl, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C4- C2ocycloalkyl, C5-C2ocycloalkenyl, C6-C2ocycloalkynyl or combinations thereof;

R25, R26 and R27 are independently H, Ci-C2oalkyl, C6-C2oaryl, C2-C2oalkenyl, C2- C2oalkynyl, C6-C2oaryl, C4-C2oheteroaryl, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C4-C2ocycloalkyl, C5-C2ocycloalkenyl or C6-C2ocycloalkynyl, whereby the alkyl and cycloalkyl are uninterrupted or interrupted by O, S, NR14 or combinations thereof, and whereby the alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkenyl and cycloalkynyl are unsubstituted or substituted by pyridin- ium*Y^", maleic anhydridyl, maleimidyl, halogen, S-R14, O-R14, CO-OR14, O-CO-R14,

NR14R14', CONR14R14', NR14-CO-R14', S(=0)₂ORi4, S(=0)₂0-Z⁺ or combinations thereof, and the aryl and heteroaryl can be further substituted by Ci-C2oalkyl, C2-C2oalkenyl, C2- C2oalkynyl, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C4-C2ocycloalkyl, C5- C2ocycloalkenyl, C6-C2ocycloalkynyl or combinations thereof, whereby the pyridinium, maleic anhydridyl, maleimidyl are unsusbstituted or substituted by Ci-C2oalkyl, C2-

C2oalkenyl, C2-C2oalkynyl, C6-C2oaryl, C6-C2oaryl-0-Ri4, C7-C2oaralkyl, Cs-C2oaralkenyl, Cs-C2oaralkynyl, C4-C2ocycloalkyl, C5-C2ocycloalkenyl, C6-C2ocycloalkynyl, S-R14, O-R14, CO-OR14, O-CO-R14, N R14R14', CONR14R14', NR14-CO-R14' or combinations thereof; Ri4 and R14' are independently H or Ci-C2oalkyl.

3. An electrode layer according to claim 2, wherein n is 1 or 2;

A is a group of formula (I I a) or (l ib),

Y^" is CI^", Br, I-, SCN-, BF₄-, PF6^", CI0₄ ^", SbF6^", AsF6^", SO3^" or an organic anion selected from the group consisting of Ci-C₂₀alkyl-COO-, C₆-C2oaryl-COO-, Ci-C₂oalkyl-S(=0)₂0-, C6-C2oaryl-S(=0)₂0-, Ci-C₂oalkyl-0-S(=0)₂0-, C₆-C₂₀aryl-O-S(=O)₂O-, Ci-C₂₀alkyl- P(=0)₂0^", C₆-C₂₀aryl-P(=O)₂O-, Ci-C₂₀alkyl-O-P(=O)₂O- and C₆-C₂₀aryl-O-P(=O)₂O-, whereby the aryl is unsubstituted or substituted by 1 to 4 Ci-C₂oalkyl, or Y- is an anionic group which is part of a compound of formula (I) and is selected from the group consisting of COO-;

Ri and R₂ are independently H, Ci-C₂₀alkyl or C6-C₂oaryl;

or Ri can additionally be D;

R₂9 is Ci-C₂oalkyl, O^", 0-Ci-C₂oalkyl or C7-C₂₀aralkyl substituted at the aryl by 1 Ci- Cealkyl;

G is -R₂₈-COOH or -R₂₈-COO Z⁺;

R₂8 is a direct bond, C₂-C₄alkenylene or Cearylene;

of formula (I) as part of group A; (III),

ndently d-Csalkyl, C₂-Csalkenyl, C6-C₂oaryl, C₄-C₂₄heteroaryl, C7-C₂oaralkyl, Cs-C₂oaralkenyl, Cs-Cioaralkynyl or C5-Ci₂cycloalkyl, whereby the alkyl, alkenyl, aryl, heteroaryl, aralkyi, aralkenyl, aralkynyl and cycloalkyi, are unsubstituted or substituted by tetrahydrofuranyl, halogen, S-Ri₄, 0-Ri₄, CO-ORi₄, 0-CO-Ri₄, NRi₄Ri₄', CONRi₄Ri₄', NRi₄-CO-Ri₄' or combinations thereof, and the aryl and heteroaryl can be further substituted by d-Csalkyl, C₂-Csalkenyl or Cs-C₂oaralkenyl;

H H

or Ri7 and R₂o form together with the N-atom R17 and R18 are attached to ²_ ²

N

H₂ H₂ H₂ H₂ H₂ H₂ H H

N ₂ ' ^N O N s or ^"NH , whereby in each of said groups one or more H-atom can be replaced by Ci-C2oalkyl, C6-C2oaryl or combinations thereof, in each of said groups two geminal H-atom can be replaced by Ci- C2oalkylidene, and/or in each of said groups two vicinal H-atoms can be replaced by benzo, trimethylene or tetramethylene, whereby the benzo is unsubstituted or substituted by methyl (fluoren-9-ylidene);

Ri5 is H, NR25R26, OR₂₅, SR₂₅, O-CO-R25 or NR25-CO-R26;

R25 and R26 are independently H, Ci-C-ualkyl, Cearyl or Cz-Cioaralkyl, whereby the al- kyl, aryl and aralkyi are unsubstituted or substituted by pyridinium^*Y-, halogen, S-R14, O-R14, CO-OR14, O-CO-R14, NR14R14', CONR14R14', NR14-CO-R14' or combinations thereof, and the pyridinium and aryl can be further substituted by d-Csalkyl;

Ri4 and R14' are independently H or Ci-C2oalkyl.

4. An electrode layer according to claim 3, wherein n is 1 ;

A is a group of formula (I la),

Y- is CI-, Br or h;

R29 is Ci-Csalkyl;

R28 is a direct bond;

D is a group of formula (III),

Ri7 is d-Csalkyl;

H₂ H₂ or Ri7 and R20 form together with the N-atom R17 and R18 are attached to

H₂

H₂C ^CH2

_/C-C. ^;

N H R18 is Ci-Csalkyl, C6-C24heteroaryl or C6-C2oaryl, whereby the aryl is substituted by Cs- C2oaralkenyl;

Ri5, Rig, R20 and R21 are H.

5. An electrode layer according to claim 1 , wherein n is 1 or 2;

A is a group of formula (I I a) or (l ib),

, CI^", Br, I-, SCN-, BF₄ ^", PF₆ ^"

rom the group consisting of Ci- C₂₀alkyl-COO-, C₆-C2oaryl-COO-, Ci-C₂oalkyl-S(=0)₂0-, C6-C2oaryl-S(=0)₂0-, Ci- C₂oalkyl-0-S(=0)₂0-, C6-C2oaryl-0-S(=0)₂0-, Ci-C₂oalkyl-P(=0)₂0-, C6-C2oaryl-P(=0)₂0- , Ci-C₂oalkyl-0-P(=0)₂0- and C6-C2oaryl-0-P(=0)₂0-, whereby the aryl is unsubstituted or substituted by 1 to 4 Ci-C2oalkyl, or Y- is an anionic group which is part of a compound of formula (I) and is selected from the group consisting of COO-; Ri and R2 are independently H, Ci-C2oalkyl or C6-C2oaryl;

or Ri can additionally be D; R29 is Ci-C2oalkyl, O^", 0-Ci-C2oalkyl or C7-C2oaralkyl unsubstituted or substituted at the aryl by 1 d-Csalkyl;

G is -R28-COOH or -R₂₈-COO Z⁺;

R28 is a direct bond, d-dalkenylene or Cearylene;

//

of formula (I) as part of group A; D is a group of formula (III),

ndently d-Csalkyl, d-Csalkenyl, C6-C2oaryl, C₄-C2₄heteroaryl, C7-C2oaralkyl, Cs-doaralkenyl, Cs-doaralkynyl or C5-Ci2cycloalkyl, whereby the alkyl, alkenyl, aryl, heteroaryl, aralkyi, aralkenyl, aralkynyl and cycloalkyi, are unsubstituted or substituted by tetrahydrofuranyl, halogen, S-Ri₄, 0-Ri₄, CO-ORi₄, 0-CO-Ri₄, NRi₄Ri₄', CONRi₄Ri₄', NRi₄-CO-Ri₄' or combinations thereof, and the aryl and heteroaryl can be further substituted by d-Csalkyl, d-Csalkenyl or Cs-doaralkenyl;

or Ri7 and R20 and/or R18 and R19 form together with the N-atom R17 and R18 are at-

H₂ H₂ H₂ H₂ H₂ H₂ H₉ H₉

tached to _c ²__c ² , N CH₂ , N O S ₀r ^U~NH , whereby in each of said groups one or more H-atom can be replaced by Ci-C2oalkyl, C6-C2oaryl or combinations thereof, in each of said groups two geminal H-atom can be replaced by Ci-C2oalkylidene, and/or in each of said groups two vicinal H-atoms can be replaced by benzo, trimethylene or tetramethylene, whereby the benzo is unsubstituted or sub- stituted by methyl (fluoren-9-ylidene);

Ri5 is H, NR25R26, OR₂₅, SR₂₅, O-CO-R25 or NR25-CO-R26;

R25 and R26 are independently H, Ci-Ci₄alkyl, Cearyl or C7-Cioaralkyl, whereby the alkyl, aryl and aralkyi are unsubstituted or substituted by pyridinium^*Y-, halogen, S-Ri₄, 0-Ri₄, CO-ORi₄, 0-CO-Ri₄, NRi₄Ri₄', CONRi₄Ri₄', NRi₄-CO-Ri₄' or combinations thereof, and the pyridinium and aryl can be further substituted by d-Csalkyl;

Ri₄ and Ri₄' are independently H or d-doalkyl.

6. An electrode layer according to claim 5, wherein n is 1 ;

A is a group of formula (I la),

R29 is Ci-C2oalkyl or C7-C2oaralkyl;

R28 is a direct bond;

D is a group of formula (I I I),

Ri7 and R18 are independently d-Csalkyl, Cearyl substituted by Cs-C2oaralkenyl or are C4-C24heteroaryl;

or Ri7 and R20 and/or R18 and R19 form together with the N-atom R17 and R18 are attached to

N

R25 is Ci-Ci4alkyl or Cz-Cioaralkyl.

7. An electrode layer according to any of claims 1 -6, wherein the oxide semiconductor fine particles are made of ΤΊΟ2, Sn0₂, W0₃, ZnO, Nb₂0₅, Fe₂0₃, Zr0₂, MgO, W0₃, ZnO, CdS, ZnS, PbS, Bi₂S₃, CdSe, CdTe or combinations thereof.

8. An electrode layer according to any of claims 1 -7, wherein the porous film made of oxide semiconductor fine particles is sensitized with a dye of formula (I) and one or more further dyes.

9. An electrode layer according to claim 8, wherein the further dye is a metal complex dye and/or an organic dye selected from the group consisting of indoline, courmarin, cyanine, merocyanine, hemicyanine, methin, azo, quinone, quinonimine, diketo-pyrrolo- pyrrole, quinacridone, squaraine, triphenylmethane, perylene, indigo, xanthene, eosin, rhodamine and combinations thereof.

10. An electrode layer according to any of claims 1 -9, wherein the dye is adsorbed together with an additive.

1 1 . An electrode layer according to claim 10, wherein the additive is a co-adsorbent, preferably a steroid, a crown ether, a cyclodextrine, a calixarene, a polyethyleneoxide or combinations thereof.

12. A photoelectric conversion device comprising an electrode layer as defined in any of claims 1 -1 1 .

13. A dye sensitized solar cell comprising a photoelectric conversion device as defined in claim 12.

14. Use of a compound of formula (I) as defined in any of claims 1 -6 as a dye in a dye sensitized solar cell.

15. A compound of formula (I) as defined in any of claims 1 -6.